Philip P. answered 02/17/18
Tutor
4.9
(484)
Effective and Patient Math Tutor
h = 400 − 16t2
16t2 = 400 - h
4t = ±√(400-h)
t = ±(1/4)√(400-h)
Plug in h = 300 and compute the t. Use the positive value.